The present invention relates to an apparatus and method for filling containers and, more particularly, to an automated apparatus and method for filling septum-sealed containers.
Septum-sealed containers are often used to store sterile or hazardous fluids. Sterile liquids, such as medicines, require special handling and storage precautions so that they do not contact the environment and become contaminated. Other liquids, such as environmental samples, also require special handling precautions so that the samples do not become contaminated. Likewise, hazardous liquids require special handling and storage precautions so that they do not escape into and contaminate the environment. In order to prevent these liquids from coming into contact with the environment, they are typically stored in a septum-sealed container, such as a septum-sealed vial. The septum of a septum-sealed vial is typically made from a pliable polymer, such as a rubber material, that is readily pierced by a needle and that seals itself upon removal of the needle. The needle is used to pierce the septum in order to add fluids to the vial. Likewise, the needle may be used to pierce the septum in order to remove fluids from the vial. When the needle pierces the septum, it forms a hole that is just wide enough to allow the needle to pass through the septum. The pliability of the septum creates a seal between the needle and the septum when the needle is in the septum. This seal prevents the fluid within the vial from contacting the environment when the needle is in the septum. An objective in piercing the septum is to avoid ripping or otherwise damaging the septum, which would prevent the septum from sealing with the needle. Likewise, another objective in piercing the septum is to assure that the hole created by the needle seals itself upon removal of the needle, which prevents the fluid within the container from being exposed to the environment.
In some applications, automated filling devices are used to fill the vials. For example, a drug company may use an automated filling device to fill septum-sealed vials with sterile drugs. Other industries may use automated filling devices that are remote from human intervention to keep operators from exposure to the fluids. For example, in a situation where hazardous fluids are required to be delivered to a container, it is generally safer to handle these containers without human exposure to the liquids.
These automated filling devices, however, have several disadvantages. One disadvantage with automated filling devices is that they have a tendency to move the container relative to the needle as the needle pierces the septum. This movement of the container relative to the needle can damage the needle, the septum, or both. If the septum becomes damaged, it will not properly seal the container and the fluid within the container will be exposed to the environment. Another disadvantage with automated filling devices is that they do not provide for easy cleaning of the needle. An unclean or contaminated needle may contaminate the fluid within the container.
Therefore, a need exists for an automated container filling device that does not damage septa used to seal the containers and that may be easily cleaned.
The present invention is directed toward an apparatus and method for delivering fluids into a container. The apparatus has a holder mechanism and a carriage, wherein the carriage is movable along an axis relative to the holder mechanism. The holder mechanism serves to hold the container in a fixed position during the filling process. The carriage has a piston attached to it and a cylinder having a hole formed therein is slidably attached to the piston along the axis. A needle extending along the axis is attached to the piston and passes through the hole in the cylinder. The association between the piston and the cylinder forms a chamber within the cylinder. The needle has a first operative position relative to the cylinder when the chamber has a first volume and the needle has a second operative position relative to the cylinder when the chamber has a second volume. In the first operative position, the needle may, as a non-limiting example, be recessed within the cylinder. In the second operative position, the needle may, as a non-limiting example, extend from the cylinder.
Using the apparatus to deliver a fluid to a container involves moving the carriage along the axis away from the holder mechanism. The chamber within the cylinder is filled with a fluid, which causes the cylinder to move toward the holding mechanism and sheaths the needle within the cylinder. A container may then be placed on the holding mechanism without the container inadvertently contacting the needle. The carriage is then moved along the axis toward the container to a point where the cylinder contacts the container. The movement of the carriage along the axis toward the holder mechanism continues as the fluid within the chamber is vented, which reduces the volume of the chamber and allows the needle to extend from the cylinder. The force exerted on the container by the cylinder is proportional to the rate at which the fluid is vented from the cylinder and the rate at which the carriage moves toward the container. When the needle has entered the container, a fluid is passed through the needle and into the container. In the situation where the container has a septum seal, the needle pierces the septum as the fluid is vented from the chamber.
Removing the needle from the container commences with filling the chamber with a fluid, which increases the volume of the chamber. Increasing the volume of the chamber maintains a force on the container exerted by the cylinder, and causes the piston and carriage to move away from the container. As the piston moves away from the container, the needle attached to the piston is removed from the container. When the needle has been removed from the container, the carriage is moved along the axis away from the container. The above-described force applied to the container assures that a septum pierced by the needle is not damaged by movement of the container relative to the needle as the needle is removed from the septum.
An embodiment of the above-described apparatus also provides for a mechanism that cleans the needle. The holder mechanism has a first hole formed therein that is positioned to receive the needle. A second hole in the holder mechanism intersects the first hole. During the cleaning process, the carriage and cylinder are moved so that the needle is positioned in the first hole. Cleaning solutions are injected through the needle or the second hole to clean the needle.